Question

我有一个嵌套的哈希：

given =  {
  "AA" => {
     :GE => nil,
    "GE" => "successful",
     :GR => nil,
     :ZG => nil,
    "ZG" => "successful",
  },
  "BB" => {
    :MM => nil,
    "MM" => "successful",
     :GR => nil,
     :ZZ => nil,
    "ZZ" => "successful",
  }
}

，我的目标是将其转换为新的哈希，而无需重复。：GE /“ GE”和：ZG /“ ZG”等。

goal = {
  "AA" => {
    :GE => "successful",
    :GR => nil,
    :ZG => "successful",
  },
  "BB" => {
    :MM => "successful",
     :GR => nil,
    :ZZ => "successful",
  }
}

我的尝试是使用Rails方法index_by

given.map do |key, value|
  value.index_by {|r| value[r]}
end

或使用

given.each { |key,value| temp_hash = {} (value.each { |va| va[0].each { |k,v| temp_hash|key| << val }}) given_hash[k.to_sym] = temp_hash if given.has_key?(k.to_sym)}

但是我有点卡住了。任何帮助将不胜感激！

Answer 1

我假设在{ :GE => nil, "GE" => "successful" }的情况下，您要使用第一个真实值（“成功”）并确保键是符号：

result = given.transform_values do |inner_hsh|
  inner_hsh.group_by do |k,v|
    k.to_sym
  end.transform_values do |key_vals|
    key_vals.to_h.values.find(&:itself)
  end
end

Answer 2

假设@max的假设是正确的，并且内部哈希中键的顺序也不重要，这是产生所需返回值的另一种方法。

given.each_with_object({}) do |(k,v),h|
  h[k] = v.sort_by { |_,w| w.nil? ? 1 : 0 }.uniq { |m,_| m.to_s }.to_h
end
  #=> {"AA"=>{"GE"=>"successful", "ZG"=>"successful", :GR=>nil},
  #    "BB"=>{"MM"=>"successful", "ZZ"=>"successful", :GR=>nil}}

请参见Array#uniq，尤其是这样的句子：“依次遍历自我，并保持第一次出现。”

对于

k = "AA"
v = { :GE=>nil, "GE"=>"successful", :GR=>nil, :ZG=>nil, "ZG"=>"successful" }

我们计算

a = v.sort_by { |_,w| w.nil? ? 1 : 0 }
  #=> [["GE", "successful"], ["ZG", "successful"],
  #    [:GE, nil], [:GR, nil], [:ZG, nil]] 
b = a.uniq { |m,_| m.to_s }
  #=> [["GE", "successful"], ["ZG", "successful"], [:GR, nil]]

因为"GE"在:GE之前，而"ZG"在:ZG之前。最后，

h[k] = b.to_h
  #=> {"GE"=>"successful", "ZG"=>"successful", :GR=>nil}

摆脱嵌套哈希中的“重复项”

2 个答案: